The use of various phenol compounds as electron-accepting compounds in pressure-sensitive or heat-sensitive recording material has been described in U.S. Pat. Nos. 3,244,549 and 3,244,550, and British Pat. No. 1,135,540, etc. However, these phenol compounds cannot be considered fully satisfactory, in that none of them is capable of giving a desirably high color density when used in combination with electron donating colorless dyes.
Benzyl-p-hydroxybenzoate which is described in U.S. Pat. No. 4,399,188 is also unsatisfactory as a material for heat-sensitive recording material, for it does not provide sufficient resistance to moisture and heat of colored images, and benzyl-2,4-dihydroxybenzoate which is disclosed in Japanese Patent Application (OPI) No. 209590/83 (corresponding to British Pat. No. 2,122,763A) (the term "OPI" as used herein refers to a "published unexamined Japanese patent application") is also unsatisfactory as a material for heat-sensitive recording material, for it does not provide sufficient resistance to moisture and heat, and it also gives rise to a fogging problem.